The present invention relates to ventilation devices in motor vehicles, especially such vehicles as vans and campers. In particular, the invention relates to a combination of air scoop and air vent for the roof top of a motor vehicle.
With the increasing popularity of recreational motor vehicles such as vans and campers, various means have been devised to provide fresh air ventilation through the body of the vehicle. Such devices are usually mounted on the roof of the vehicle and direct air into and out of the vehicle through a hole in the roof. Among such devices are those known as air scoops which direct air into the vehicle, the air then being exhausted through the windows of the vehicle, and air vents which direct air which has been drawn into the vehicle through the windows out of the vehicle. Increasingly popular are those devices which can function both as scoops and vents. One of the most popular of such combination devices is simply a lid which is liftable vertically upward from a frame around a hole in the roof of the vehicle. However, the liftable lid type device is prone to several shortcomings. Firstly, any scooping effect of air into the body of the vehicle is relatively weak inasmuch as air flows directly through the device creating a venturi-type action which sucks air out of the vehicle. Furthermore, the lifting lid type device allows rain to enter the vehicle during the venting operation. Moreover, such devices are prone to damage if they are opened when the vehicle is traveling at a high speed or when there is a strong wind. In short, such devices are unsuitable for use in inclement weather and function weakly, if at all, as scoops. If any case such devices cannot be made to function only as scoops.
Another combination scoop/vent device is that which consists of a lid which can be lifted from a frame surrounding the hole in the roof in one of three ways: lifted at the front, it functions as a scoop; lifted at the rear, it functions as a vent; and lifted straight up, it functions as a venturi vent much as the lifting top type device. While this latter type device can function independently as a vent or a scoop, the fact that the top of the device must be lifted from the roof of the vehicle again makes such devices prone to damage in strong winds or during high-speed travel.